Lufa Farms’ second greenhouse, located in Laval, Quebec, opened August 2013. The greenhouse houses tomatoes and eggplants. Photo credit:Lufa Farms

When room to farm in a city is scarce, look up.

Montreal-based Lufa Farms built Canada’s first commercial hydroponic urban rooftop greenhouse in 2011. In the late summer of 2013, Lufa opened a second, larger rooftop greenhouse in Laval, Quebec.

Although Lufa always intended to add another greenhouse to its operation once the 2011 site opened, the company wanted to observe how the first project did first, says Lauren Rathmell, greenhouse director and founding member.

“The goal was to have by the end of our first year of production 1,000 subscribers, which is about what our first site can support by itself,” she says. “The trajectory from there was to have a goal of having 3,500 subscribers by the end of 2013.”

Lufa Farms easily achieved that number once the second greenhouse opened.

“From here we want to be up to 6,000 subscribers by the end of this year between the two greenhouses,” Rathmell says.

Lufa Farms partnered with an industrial commercial developer in Montréal to help build the second greenhouse.

“They actually designed the building to accommodate the greenhouse,” Rathmell says. “It was part of a new construction, which is definitely different than our first project that was built on an existing building. It worked out in that they were planning the building and we designed it with them to have the greenhouse integrated into the building from the get-go.”

Kubo, a greenhouse company, also helped design and construct the second greenhouse.

“It’s a higher-tech greenhouse,” Rathmell says. “Overall, the greenhouse is about one and a half times the size of our first site.”

The new facility is a semi-closed greenhouse, a new concept developed by Kubo.

“The advantage is that more light gets into the greenhouse because there is less structure that shades it, and there is also less pest pressure because there’s a higher pressure inside the greenhouse than on the outside,” she says.

According to Rathmell, it takes about 50 square feet of greenhouse area to feed one person fresh vegetables.

“Between the two greenhouses, we can feed about 7,000,” she says. “The first greenhouse was really a testing ground and we wanted to use what we learned to get the new greenhouse going,” she says.

In terms of production, the two greenhouses complement one another. Both use hydroponic growing methods featuring water conservation, rainwater capture, biological pest control, energy conservation practices and on-site compost facilities.

“When we opened our second greenhouse, we divided our production to have cucumbers, peppers and greens at the first house, and tomato and eggplant at the second one,” Rathmell says. “We decided to expand the varieties. We are doing 22 different tomato varieties at the new site. We wanted to do a variety trial and get people excited about the tomatoes.”

Lufa Farms uses a recirculation system for irrigation and reuses all its irrigation water in both greenhouses. But in the new greenhouse, the farm also captures rainwater and condensation.

“The condensation on the inside of the glass that runs off we capture that and use it for irrigation,” Rathmell says.

So far, the first greenhouse is profitable and the company as a whole is on track for profitability within the next couple of months, mainly because the new greenhouse has helped the Farm grow its subscriber base significantly since last year.

To save on manpower, the greenhouses have the same centralized plant science and growing teams that can remotely manage the farms.

“It’s all grouped together.” Rathmell says. “We have the two greenhouses and we pick and pack everything in the morning for a given delivery day and we take it all to our specialized distribution center, which is in the building underneath our first greenhouse. We go pick up the tomatoes from the second greenhouse in the morning and everything goes in the basket for the day and is delivered.”

In the next few years, Lufa hopes to have another greenhouse in Montréal to continue growing the Farm’s subscriber base.

“We want it to be definitely as big as the one we built to date,” says Rathmell. “And then we are hoping to expand to Boston in the next few years as well.”